1. drugs is tested on
human cells - grown in a
lab to test how safe it is,
how well it works
against the disease
2. drug is tested on an
animal as a trial, make
sure the drug works as
on animals as it does on
cells grown
3. drug is tested on
people, to check bad
side effects, see how
effective it is
Vaccinations
Using a safe
version of a
dangerous
Microorganism
They react
different to
different people
(side effects)
Homeostasis
Receptors - detect
changes in the
enviroment,
Processors - receive
information about these
changes and organise
the response and
Effectors - produce the
response to the change
Communication Pathways
Nerve Impulses -
very fast, short live
Hormones -
slower, longer
lasting effect
Water Balence
Water Inputs - drinks,
food and respiration
Water Outputs -
sweating, faeces,
breathing, and in
urine
Urine balances water levels by producing dilute or concentrated urin
How the heart works
Types of Blood vessels
Arteries - carry blood away
from the heart, have thick
walls, high blood pressure, strong and elastic
Veins - carry blood back to the
heart, thin walls, lower blood
pressure
Capillaries - branches of the
arteries that are really thin,
supply nutrients and oxygen,
thin walls - substances move
quickly and easily
Coronary arteries -
supply the heart cells
with food and
nutrients